1. Field of the Invention
The invention concerns an air conditioning device for a seat.
The words "seat,""seating surface,""seating ventilation,""sitting," and "air conditioning device for a seat" utilized in the following include both seats in the narrow sense and seat back rests, i.e. they additionally comprise in the following the terms "seat back rest,""seat back rest surface,""seat back rest ventilation,""leaning against," and "air conditioning device for a seat surface."
In the current state of the art, various seat heating devices and air conditioning devices for a seat with a channel system in the seat's padding are known. WO 95/14899, for example, reveals an active seat ventilation system with channels in the seat's padding. This seat ventilation, however, requires a very complex seat design. Uniform air distribution over large surfaces is not guaranteed.
DE 42 00 825 A1 reveals a cloth spacer design within the seat. Compared to a channel system in the seat padding, this offers the advantage of a simpler seat design and improves the passive temperature characteristics of vehicle seats. However, to ensure sufficient moisture transfer even under difficult environmental conditions, active ventilation of the cloth spacer design through radial or axial blowers is necessary. A ventilation system through pump effects in the seat design, e.g. through compressible channels in the seat's padding, is also feasible.
From DE 40 17 707 A1 we know of a cloth spacer design that is combined with a heddle-based car seat heating system. In this case, however, the distance between the heat conductors is so large that the air flowing through the cloth spacer design is not heated during active ventilation. Due to cooling effects, this can have disadvantageous physiological consequences for the person using the seat.
DE 42 33 118 A1 reveals a heating pad made of carbon fibers which are flexible but not elastic in the crosswise and lengthwise directions. Additionally, the production of heating pads requires high carbon consumption and therefore high material costs.
DE 34 23 657 A1 describes an air conditioning device for a seat in accordance with the preamble of claim #1 with an air-permeable padded cushion that is arranged under the seat surface and a slab heating element that is arranged between the seat surface and the padded cushion. This air conditioning device for a seat represents a combination of a seat heating system of the highest comfort level regarding heating speed, homogeneous thermal distribution and elasticity with a temperature control layer for seat ventilation. Hereby the following functions are combined:
air conduction and even air distribution PA1 conventional seat heating system without seat ventilation PA1 heating of the air that is fed for seat ventilation purposes to a physiologically safe temperature level
A disadvantage of the air conditioning device for a seat described in DE 34 23 657 A1, however, consists in the fact that the base object, in this case the padded cushion, has a specific cushion thickness and therefore the air conditioning device for a seat must always be produced separately in close connection with each individual seat.